Treatment of Landfill Waste, Leachate and Landfill Gas

207 Pages·2017·4.41 MB·English

by  Hecham M. Omar

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Hecham M. Omar, The University of Western Ontario
Supervisor: Sohrab Rohani, The University of Western Ontario
A thesis submitted in partial fulfillment of the requirements for the Master of Engineering
Science degree in Chemical and Biochemical Engineering
© Hecham M. Omar 2016
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Omar, Hecham M., "Treatment of Landfill Waste, Leachate and Landfill Gas: Modelling/Simulation and
Experimental Studies" (2016). Electronic Thesis and Dissertation Repository. 3731.
https://ir.lib.uwo.ca/etd/3731
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Abstract
Landfilling has been relegated to containing waste and hoping for minimal environmental
impact. However, landfills produce harmful leachate and landfill gas that require treatment.
To speed up the landfill biodegradation process, aerating the landfill to promote aerobic
biodegradation has been implemented successfully. However, the conversion from a
traditional anaerobic landfill to an aerobic landfill is to this point, not well researched. A
3-dimensional dynamic mathematical model was developed that depicts the conversion of
a landfill from an anaerobic to an aerobic operation. The results of the model (CO volume
2
fraction and temperature), agreed with data from published work. The model solved for the
liquid and gaseous pressures/velocities, gas composition, anaerobic/aerobic biomass
concentrations and temperature; all were solved with respect to space and time. Landfill
leachate requires treatment before release and landfill gas requires purification (removal of
CO ) before it can be used as a fuel. A hybrid sorption (absorption and adsorption/ion
2
exchange) system was developed to treat leachate and purify landfill gas in the same
column. The absorption results showed that leachate could remove more carbon dioxide
from the landfill gas than pure water, due to its slight basicity. The adsorption/ion exchange
results showed that lead could be removed from model leachate but not below Ontario
discharge guidelines with the length of the column used (50-55 cm zeolite bed height).
Keywords

Anaerobic landfill, aerobic landfill, landfill gas, leachate, bioreactor landfill, finite element
method, mathematical model, absorption, adsorption
Co-Authorship Statement
Chapter 2
Article Title:
Treatment of landfill waste, leachate and landfill gas: A review
Authors:
Hecham Omar, Sohrab Rohani
Article Status: Published in Front. Chem. Sci. Eng.
Hecham Omar conducted the literature review and wrote the manuscript. The work
was supervised by Prof. Sohrab Rohani. The draft of the manuscript was reviewed by
Prof. Rohani.
Hecham Omar, Sohrab Rohani, “Treatment of landfill waste, leachate and landfill gas:
A review”. Front Chem Sci Eng, 9(1), 2015, 15-32.
Chapter 3
Article Title:
The mathematical model of the conversion of a landfill operation from anaerobic to
aerobic
Authors:
Hecham Omar, Sohrab Rohani
Article Status: Submitted to Appl. Math. Model.
Hecham Omar developed the model, ran the simulations and wrote the manuscript. The
work was supervised by Prof. Sohrab Rohani. The draft of the manuscript was
reviewed by Prof. Rohani
Appendix B
Article Title:
Transport phenomena in the conversion of an anaerobic landfill into an aerobic landfill
Authors:
Hecham Omar, Sohrab Rohani
Article Status: Published in Proceedings of COMSOL Conference 2015 Boston
Hecham Omar developed the model, ran the simulations and wrote the manuscript. The
work was supervised by Prof. Sohrab Rohani. The draft of the manuscript was
reviewed by Prof. Rohani.
Hecham Omar, Sohrab Rohani, “Transport phenomena in the conversion of an
anaerobic landfill into an aerobic landfill”. Proceedings of the COMSOL Conference
2015 Boston, 2015.
Appendix C
Article Title:
Microwave assisted zeolitization of coal fly ash using landfill leachate as the solvent
Authors:
Syed Salman Bukhari, Hecham Omar, Sohrab Rohani
ii
Article Status: Submitted to Journal of Hazardous Materials
Syed Bukhari and Hecham Omar performed the experiments. The majority of the data
analysis and manuscript writing was performed by Syed Bukhari. Hecham Omar
helped with data analysis and writing of the manuscript. The work was supervised by
Prof. Sohrab Rohani. The draft of the manuscript was reviewed by Prof. Rohani.

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Acknowledgments
I would like to acknowledge the guidance provided by Professor Sohrab Rohani.
Professor Rohani provided valuable advice and knowledge. His constant encouragement
allowed me to exceed my own expectations.
I would like to acknowledge all of my colleagues and members from my lab, for
their advice and help when needed. I would specifically like to show appreciation to Dr.
Ali Alizadeh and Dr. Hossein Kazemian who worked closely with me and provided
valuable advice. I would like to thank Chris Piccolo, Mahshid Attari and the various
laboratory technicians for performing some of the characterization tests used in my work.
I would also like to acknowledge my parents, Mohamed and Feyrouz Omar for
pushing me towards pursuing my Master’s Degree, for never losing faith and for their
unbounded support.
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Table of Contents
Abstract ................................................................................................................................ i
Co-Authorship Statement.................................................................................................... ii
Acknowledgments.............................................................................................................. iv
Table of Contents ................................................................................................................ v
List of Tables ..................................................................................................................... xi
List of Figures ................................................................................................................... xii
List of Abbreviations ........................................................................................................ xv
List of Appendices .......................................................................................................... xvii
Chapter 1 ............................................................................................................................. 1
1 Introduction .................................................................................................................... 1
1.1 Background ............................................................................................................. 2
1.1.1 Landfill waste treatment ............................................................................. 2
1.1.2 Leachate treatment ...................................................................................... 3
1.1.3 Landfill gas treatments ................................................................................ 4
1.2 Modelling methodology .......................................................................................... 5
1.2.1 Methodology ............................................................................................... 5
1.2.2 Finite element method................................................................................. 6
1.3 Sorption ................................................................................................................... 7
1.4 Objectives ............................................................................................................... 8
1.5 Motivation ............................................................................................................... 8
1.6 Thesis outline .......................................................................................................... 9
1.7 References ............................................................................................................. 10
Chapter 2 ........................................................................................................................... 14
2 Treatment of landfill waste, leachate and landfill gas: A review ................................. 14
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2.1 Introduction ........................................................................................................... 14
2.2 Landfill treatments ................................................................................................ 16
2.2.1 Dry-tomb landfill ...................................................................................... 16
2.2.2 Anaerobic bioreactor landfill .................................................................... 17
2.2.3 Aerobic bioreactor landfill ........................................................................ 19
2.2.4 Semi-aerobic bioreactor landfill ............................................................... 23
2.2.5 Landfill operations and measurements/control ......................................... 24
2.2.5.1 Operations ................................................................................... 24
2.2.5.2 Measurement/Control ................................................................. 27
2.3 Leachate treatment ................................................................................................ 28
2.3.1 Anaerobic treatment .................................................................................. 30
2.3.2 Aerobic treatment...................................................................................... 31
2.3.3 Anammox .................................................................................................. 35
2.3.4 Adsorption................................................................................................. 36
2.3.5 Chemical oxidation ................................................................................... 38
2.3.6 Coagulation/flocculation ........................................................................... 39
2.3.7 Membrane processes ................................................................................. 41
2.4 Landfill gas treatment/use ..................................................................................... 43
2.4.1 Quality of LFG .......................................................................................... 43
2.4.2 LFG recovery ............................................................................................ 44
2.4.3 Use of LFG ............................................................................................... 44
2.4.4 Flaring ....................................................................................................... 45
2.4.5 Adsorption................................................................................................. 45
2.4.6 Absorption................................................................................................. 46
2.4.7 Permeation ................................................................................................ 47
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2.4.8 Cryogenic treatments ................................................................................ 47
2.5 Conclusions ........................................................................................................... 47
2.6 References ............................................................................................................. 49
Chapter 3 ........................................................................................................................... 65
3 The mathematical model of the conversion of a landfill operation from anaerobic
to aerobic ...................................................................................................................... 65
3.1 Introduction ........................................................................................................... 65
3.2 Theory and computation technique ....................................................................... 67
3.2.1 Momentum balance ................................................................................... 69
3.2.2 Mass balance ............................................................................................. 71
3.2.3 Energy balance .......................................................................................... 78
3.2.4 Model assumptions ................................................................................... 80
3.3 Results and discussion .......................................................................................... 81
3.3.1 Geometry and meshing ............................................................................. 81
3.3.2 Anaerobic-aerobic conversion .................................................................. 83
3.3.2.1 Parameter estimation .................................................................. 83
3.3.2.2 Growth of aerobic bacteria ......................................................... 86
3.3.2.3 Oxygen consumption .................................................................. 89
3.3.2.4 Carbon dioxide production ......................................................... 91
3.3.2.5 Methane production .................................................................... 92
3.3.3 Higher aerobic biomass concentration ...................................................... 92
3.3.3.1 Full scale landfill aerobic biomass concentration ...................... 93
3.3.3.2 High aerobic biomass concentration .......................................... 93
3.3.4 Temperature control .................................................................................. 96
3.4 Conclusions and summary .................................................................................... 98
3.5 References ........................................................................................................... 100
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Chapter 4 ......................................................................................................................... 106
4 Removal of CO2 from landfill gas and Pb2+ from leachate using a hybrid sorption
process ........................................................................................................................ 106
4.1 Introduction ......................................................................................................... 107
4.2 Economic incentive for the landfill gas purification ........................................... 109
4.3 Materials and methods ........................................................................................ 111
4.3.1 Zeolite preparation .................................................................................. 111
4.3.2 Leachate preparation ............................................................................... 111
4.3.3 Model leachate solution preparation ....................................................... 111
4.3.4 Characterization techniques .................................................................... 112
4.3.5 Experimental setup and procedure .......................................................... 113
4.3.5.1 Experimental setup ................................................................... 113
4.3.5.2 Absorption column experimental procedure ............................ 114
4.3.5.3 Batch adsorption/ion exchange experimental procedure .......... 115
4.3.5.4 Adsorption/ion exchange column experimental procedure ...... 115
4.4 Results and discussion ........................................................................................ 116
4.4.1 Adsorbent characterization ..................................................................... 116
4.4.1.1 Chemical composition .............................................................. 116
4.4.1.2 Phase purity (crystallinity) and morphology ............................ 117
4.4.1.3 Thermal analysis ....................................................................... 118
4.4.1.4 Surface area .............................................................................. 119
4.4.1.5 Cation exchange capacity ......................................................... 120
4.4.2 Absorption............................................................................................... 120
4.4.2.1 Agreement between the experimental and simulated results of
absorption ................................................................................. 120
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4.4.2.2 Comparison of the performance of different packings and
absorbents ................................................................................. 121
4.4.2.3 Simulation results at higher pressures ...................................... 123
4.4.2.4 Multipass leachate absorption .................................................. 124
4.4.3 Adsorption/ion exchange ........................................................................ 127
4.4.3.1 Batch adsorption/ion exchange test; pH in the batch tests ....... 127
4.4.3.2 Continuous adsorption/ion exchange column test .................... 130
4.5 Conclusions ......................................................................................................... 131
4.6 References ........................................................................................................... 133
Chapter 5 ......................................................................................................................... 138
5 Conclusions and recommendations ............................................................................ 138
5.1 Conclusions ......................................................................................................... 138
5.2 Recommendations ............................................................................................... 140
Appendices ...................................................................................................................... 141
Appendix A Preliminary adsorption/ion exchange column results ................................ 141
A.1 Ammonium assay calibration curve.................................................................... 141
A.2 Absorption equilibrium time determination........................................................ 142
A.3 Adsorption equilibrium time determination........................................................ 143
Appendix B Transport Phenomena in the Conversion of an Anaerobic Landfill into
an Aerobic Landfill .................................................................................................... 145
B.1 Introduction ......................................................................................................... 145
B.2 Governing equations ........................................................................................... 146
B.2.1 Gas flow equation ................................................................................... 146
B.2.2 Gas transport equations ........................................................................... 147
B.2.3 Biokinetic equations................................................................................ 148
B.2.4 Species consumption/production equations ............................................ 150
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